Mobile communication has changed the way people communicate and mobile phones have been transformed from a luxury item to an essential part of everyday life. The use of mobile phones today is dictated by social situations, rather than hampered by location or technology. While voice connections fulfill the basic need to communicate, and mobile voice connections continue to filter even further into the fabric of everyday life, the mobile Internet is the next step in the mobile communication revolution. The mobile Internet is poised to become a common source of everyday information, and easy, versatile mobile access to this data will be taken for granted.
Third generation (3G) cellular networks have been specifically designed to fulfill these future demands of the mobile Internet. As these services grow in popularity and usage, factors such as cost efficient optimization of network capacity and quality of service (QoS) will become even more essential to cellular operators than it is today. These factors may be achieved with careful network planning and operation, improvements in transmission methods, and advances in receiver techniques. To this end, carriers need technologies that will allow them to increase downlink throughput and, in turn, offer advanced QoS capabilities and speeds that rival those delivered by cable modem and/or DSL service providers. In this regard, networks based on wideband CDMA (WCDMA) technology may make the delivery of data to end users a more feasible option for today's wireless carriers.
WCDMA networks may allow a mobile handset to communicate with a multiple number of base stations. This may take place, for example, during a soft-handoff from one base station to another base station that utilizes the same frequency band. On occasions, there may be handoffs from one base station to another where the two base stations use different frequencies. This may occur, for example, when a mobile station interfaces with a different wireless service provider, or for hotspots where one service provider may need to use more than one frequency. In these cases, the mobile handset may need to tune in to the frequency of the new base station. This may require additional circuitry to be able to synchronize to a second frequency of the second base station while still using the first frequency for communicating with the first base station. The additional synchronization circuitry may be an undesirable extra cost for the mobile handset.
WCDMA utilizes spread spectrum techniques that are based on scrambling a transmitted signal at a transmitter. The scrambled signal may be descrambled when it is received for processing at a receiver. The transmitter may utilize a scrambling code to scramble the signal and the receiver may utilize a corresponding descrambling code to descramble the received scrambled signal.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.